The asymmetric unit of the title compound, C20H14Cl3NO, consists of two independent mol­ecules. In one mol­ecule, the chlorinated benzene ring forms dihedral angles of 12.00 (9) and 77.04 (9)° with the phenyl rings. The dihedral angle between the phenyl rings is 80.37 (10)°. The corresponding dihedral angles for the other mol­ecule are 26.34 (10), 62.98 (10) and 88.47 (11)°, respectively. One of the mol­ecules features an intra­molecular C—H⋯O hydrogen bond, which forms an S(6) ring motif. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into [100] chains. The chains are further linked by C—H⋯O and C—H⋯Cl hydrogen bonds into a three-dimensional network.

Related literature

For general background to and related structures of the title compound, see: Fun et al. (2011a,b, 2012a,b). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986). For hydrogen-bond motifs, see: Bernstein et al. (1995).

For general background to and related structures of the title compound, see: Fun et al. (2011a,b, 2012a,b). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Diphenylacetic acid (0.212 g, 1 mmol), 2,4,5-trichloroaniline (0.196 g, 1 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (1.0 g, 0.01 mol) were dissolved in dichloromethane (20 ml). The mixture was stirred in the presence of triethylamine at 273 K for about 3 h. The contents were poured into 100 ml of ice-cold aqueous hydrochloric acid with stirring. The concoction was extracted thrice with dichloromethane. The organic layer was washed with saturated NaHCO3 solution and brine solution, dried and concentrated under reduced pressure to give the title compound (I). Colourless needles were grown from ethanol solution by the slow evaporation method (m.p.: 391-393K).

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Footnotes

Acknowledgements

The authors thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160). BN also thanks UGC, New Delhi, and the Government of India for the purchase of chemicals through the SAP-DRS-Phase 1 programme.

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